Brake disc thickness

[curious george]

Just trying to get a feel for when people replace their brake discs.
The wear limit on mine is 4mm.
The original was about 4.5mm.
With a micrometer I measure 4.13mm.
Is this cutting it a bit fine for a race bike? Or nah, go hard till they look likt paper?
What do people think is a good time to replace them?
50% worn? (4.25mm) 80%? (4.10mm)
:baby:

[Yokai]

I haven't got a micrometer and I haven't replaced the discs since I bought the bike!

[Skunk]

I think this has been covered before - hasn't the disc got a min thickness stamped on them?

[FROSTY]

George --its really hard to advise on this one mate. optimum thickness equally optimum head dispersal etc--BUT --heck mate if ya aint using ya brakes much Id let her wear to the wear limits.

[riffer]

Use them until the WOF inspector won't pass them or until you just can't handle the way they make the bike shudder when you put the brakes on any more ... :shifty: